Advances in minimally invasive surgical technology could dramatically increase the number of surgeries performed in a minimally invasive manner. Minimally invasive medical techniques are aimed at reducing the amount of extraneous tissue that is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. The average length of a hospital stay for a standard surgery may also be shortened significantly using minimally invasive surgical techniques. Thus, an increased adoption of minimally invasive techniques could save millions of hospital days, and millions of dollars annually in hospital residency costs alone. Patient recovery times, patient discomfort, surgical side effects, and time away from work may also be reduced with minimally invasive surgery.
The most common form of minimally invasive surgery may be endoscopy. Probably the most common form of endoscopy is laparoscopy, which is minimally invasive inspection and surgery inside the abdominal cavity. In standard laparoscopic surgery, a patient""s abdomen is insufflated with gas, and cannula sleeves are passed through small (approximately xc2xd inch) incisions to provide entry ports for laparoscopic surgical instruments. The laparoscopic surgical instruments generally include a laparoscope (for viewing the surgical field) and working tools. The working tools are similar to those used in conventional (open) surgery, except that the working end or end effector of each tool is separated from its handle by an extension tube. As used herein, the term xe2x80x9cend effectorxe2x80x9d means the actual working part of the surgical instrument that is manipulatable for effecting a predetermined treatment of a target tissue, and can include clamps, graspers, scissors, staplers, and needle holders, for example. The terms xe2x80x9csurgical instrumentxe2x80x9d, xe2x80x9cinstrumentxe2x80x9d, xe2x80x9csurgical toolxe2x80x9d, or xe2x80x9ctoolxe2x80x9d refer to a member having a working end which carries one or more end effectors to be introduced into a surgical site in a cavity of a patient, and is actuatable from outside the cavity to manipulate the end effector(s) for effecting a desired treatment of a target tissue in the surgical site. The instrument or tool typically includes a shaft carrying the end effector(s) at a distal end, and is preferably servomechanically actuated by a telesurgical system for performing functions such as holding or driving a needle, grasping a blood vessel, and dissecting tissue.
To perform surgical procedures, the surgeon passes these working tools or instruments through the cannula sleeves to an internal surgical site and manipulates them from outside the abdomen. The surgeon monitors the procedure by means of a monitor that displays an image of the surgical site taken from the laparoscope. Similar endoscopic techniques are employed in, e.g., arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy, cisternoscopy, sinoscopy, hysteroscopy, urethroscopy and the like.
Minimally invasive telesurgical robotic systems are being developed to increase a surgeon""s dexterity when working within an internal surgical site, as well as to allow a surgeon to operate on a patient from a remote location. In a telesurgery system, the surgeon is often provided with an image of the surgical site at a computer workstation. While viewing a three-dimensional image of the surgical site on a suitable viewer or display, the surgeon performs the surgical procedures on the patient by manipulating master input or control devices of the workstation. The master controls the motion of a servomechanically operated surgical instrument. During the surgical procedure, the telesurgical system can provide mechanical actuation and control of a variety of surgical instruments or tools having end effectors such as, e.g., tissue graspers, needle drivers, or the like, that perform various functions for the surgeon, e.g., holding or driving a needle, grasping a blood vessel, or dissecting tissue, or the like, in response to manipulation of the master control devices.
A typical surgery employs a number of different surgical instruments. When a different tool is desired during the surgical procedure, the surgical instrument is typically withdrawn from the surgical site so that it can be removed from its associated arm and replaced with an instrument bearing the desired end effector. The desired surgical instrument is then inserted into the surgical site. A surgical instrument may also be withdrawn from a surgical site for reasons other than to replace the end effector. For example, the loading of a clip in a clip applier used in affixing tissue typically occurs outside of the patient""s body. Each time a new clip is desired, the clip applier is removed from the surgical site to load the clip and then reintroduced into the patient""s body to apply the clip.
Tool exchange for a robotic system takes time. Moreover, it may be difficult to bring the new tool into the field of view manually after a tool change operation. It is also possible for the operator to misjudge the depth of insertion and place the tool too deep into the surgical site, which may cause unintended contact between the tool and the patient""s anatomy. To avoid such contact, the operator is likely to move the new tool very slowly into the surgical site. These factors contribute to make a tool change operation a time-consuming process.
The present invention is generally directed to robotic surgery methods, devices, and systems. The invention overcomes the problems and disadvantages of the prior art by providing a guided tool change procedure to facilitate guidance of a new tool after a tool change operation back into close proximity to the operating position of the original tool prior to its removal from the surgical site. The invention does so by recording the operating position of the original tool and calculating control parameters based on the operating position and the configuration of the new tool to guide the new tool easily and precisely into the vicinity of the operating position. In this way, the tool change procedure can be safer, more accurate, and less time-consuming, thereby minimizing xe2x80x9cdown timexe2x80x9d and risk of injury to the patient.
In accordance with an aspect of the present invention, a method of performing minimally invasive robotic surgery in a body cavity of a patient comprises recording an operating position at which a first robotic surgical tool is disposed inside the cavity. The first robotic surgical tool is removed from the cavity. The method further includes determining the desired location within the body cavity of a second robotic tool based on the recorded position of the first robotic tool. The second robotic surgical tool is introduced into the cavity and guided to the desired location in close proximity to the operating position.
In some embodiments, the second robotic surgical tool is automatically or manually guided to a target space comprising the recorded position of the first tool""s distal end with the target space being defined in part by the recorded position. The target space may be defined to include a maximum allowable depth which limits the depth of insertion of the distal end of the second robotic surgical tool in the cavity. For instance, the second robotic surgical tool may be placed with the distal end disposed within a preset distance from the sensed position of the distal end of the first robotic surgical tool. The second robotic surgical tool may be introduced into the cavity substantially via a straight line from the port of entry of the cavity to the target space.
In accordance with another aspect of the invention, a method of performing minimally invasive robotic surgery in a body cavity of a patient comprises recording an operating position at which a first robotic surgical tool is disposed inside the cavity. The first robotic surgical tool is decoupled from the slave manipulator and removed from the cavity. The method further includes determining the desired position within the body cavity of a second robotic tool based on the recorded position of the first robotic tool. The second robotic surgical tool is coupled with the slave manipulator, and introduced into the cavity. The second tool is guided to the desired position in close proximity to the operating position.
In accordance with another aspect of the present invention, a surgical robotic system comprises a slave manipulator for coupling with and actuating a robotic surgical tool inside a body cavity of a patient. A controller is configured to control movement of the slave manipulator and the robotic tool, and comprises a computer. At least one sensor is coupled with the slave manipulator for sensing an operating position of the robotic surgical tool coupled with the slave manipulator. The computer includes a first set of computer instructions for controlling the slave manipulator, after the first robotic surgical tool is removed from the cavity and decoupled from the slave manipulator, to automatically position the slave manipulator so that the second robotic surgical tool can be guided to a location in close proximity to the sensed operating position.
Another aspect of the invention is a method of delivering a robotic surgical instrument having a distal tip to a surgical site. The method comprises determining, via a computer, a target space for a preset portion of the robotic surgical instrument (such as its distal tip) to occupy upon delivery to the surgical site, and guiding delivery of the instrument to the surgical site such that the instrument is delivered into the target space.
In some embodiments, the guiding delivery comprises guiding delivery of the instrument in one degree of movement along an insertion axis. The instrument comprises a proximal shaft, a wrist member movably coupled to the shaft at a first joint, and an end effector movably coupled to the wrist member at a second joint. Movement around the first and second joints provide the end effector with multiple degrees of freedom of movement relative to the shaft. The multiple degrees of movement are constrained during delivery of the instrument to the surgical site.